Implantable Converter Defibrillators

An abnormal heart rhythm, called an arrhythmia, occurs when there is a change in the speed or pattern of electrical impulses within the heart. Arrhythmias can cause the heart to beat too slowly or two rapidly, thereby interfering with the heart's ability to pump blood effectively.

What is an implantable converter defibrillator?

An implantable converter defibrillator (ICD) is a small device that corrects abnormalities in the heart's rhythm and can prevent sudden death caused by dangerous arrhythmias. This device, which is similar to a pacemaker, is implanted under the skin, most often in the shoulder area just below the collarbone. An ICD senses the rate of the heartbeat; it delivers an electrical impulse to regulate a heart rate that is too fast. ICDs that are implanted today can also function as pacemakers that continuously regulate heart rhythm and prevent the heart from beating too slowly.

Multiple studies have demonstrated that ICD's can save the lives of individuals who are at high risk of sudden death. These include patients who have previously had heart attacks, those with congestive heart failure, and in certain types of inherited heart disease.

How is an ICD implanted?

Most ICDs are now implanted under the skin in the chest. They consist of wires (leads) which are inserted in a vein in the shoulder region or beneath the collarbone. Under x-ray guidance, the leads are advanced to the heart where they permit the ICD to detect the heart's rhythm and deliver therapy. Different types of ICDs can contain one or more leads. You and your physican can discuss the model that is best for your condition.